The invention is based on an apparatus for injecting fuel into combustion chambers of internal combustion engines, in particular self-igniting combustion engines. In a known apparatus of this general type (French Pat. No. 1,382,697), the injector effect of the injected stream produces a severely negative pressure in the conduit of the glow body, which cannot be compensated for, because there are no ventilation openings at the side of the glow body or because a ventilation gap between the injection nozzle and the glow body is lacking. Instead, air is periodically forced in a compulsory manner into the conduit of the glow body counter to the direction of the injected stream and passing to one side of the injected stream. This has a very unfavorable effect on the direction, shape and speed of the injected stream. The injected stream flutters and undergoes inward compression at one side. It loses speed and is poorly distributed in the combustion chamber. This results in not only increased emission of soot but also losses of power.